Insulated Glazing Units (IGUs) are used to reduce thermal loss through architectural exterior wall windows. A typical IGU includes two panes, a spacer frame, and a cavity formed by these three elements. Microoptical elements integrated into an IGU can be used to redirect some of the sunlight passing through the IGU to an interior ceiling, to augment conventional interior lighting, thereby increasing the energy efficiency of buildings. In many cases, it can be convenient to integrate the microoptical elements directly on the glass of the window, e.g., by applying refractive or diffractive optical structures to the surface of the glass. Microoptics applied to the outside surface of an IGU can be adversely impacted by several factors, including soiling and abrasion. It would be advantageous to apply microoptics to the glass surfaces within the cavity of an IGU; however, such structures must exhibit photo- and thermal-stability so that the clean environment within the IGU is maintained.